dc.description.abstract | In this study, a feasible route for preparing polyaniline/polystyrene core shell latex was developed. The monodisperse nonionic polystyrene latex and poly(styrene co sodium styrene sulfonate) latex were synthesized by dispersion polymerization method, using styrene as monomer, polyvinylpyrrolidone as stabilizer, 2-2-azobis-isobutyronitrile as initiator. The monodisperse anionic polystyrene latex was also synthesized by emulsifier-free emulsion polymerization method, using styrene as monomer, potassium peroxodisulfate as initiator. Then aniline was polymerized on the surface of polystyrene latex. The core-shell composites were formed and studied by SEM, TEM, IR, Zeta potential, elemental analysis, XPS and conductivity measurements.
Anilinium ions are adsorbed on the surface of polystyrene latex by columbic interaction between the sulfonate groups of poly(styrene co sodium styrene sulfonate) and negative charges on anionic polystyrene latex. After polymerization, more uniform polyaniline shell structures were obtained. We can control the amounts of polyaniline by adjusting the weight ratio of aniline monomer and polystyrene latex in mother liquids. The conductivity of the core-shell composites can be improved.
Although the particle sizes of the core and core-shell composites are not very uniform, the thickness of polyaniline shell in the core-shell composites cannot be determined, but the color, elemental analyses, and XPS results show that polyaniline is formed on polystyrene latex.
Polymerization of aniline in mother liquid containing the same quantity of aniline monomers on more negatively charged polystyrene latex results in more conductive composites. The suspensions of nonionic polystyrene latex and poly(styrene co sodium styrene sulfonate) latex are more stable than that of the anionic polystyrene latex. SEM and TEM photographs indicate the distribution of the particle sizes is wider for polystyrene copolymer latex, but the stability of the suspension and conductivity are higher for the composites. Improvement of the uniformity of the latex particles will be the objective of future study. | en_US |